1. Field of the Invention
The invention relates to a water or spirit level composed of an elongated body, preferably of metal, at least one bubble mounted in the elongated body, and end caps, preferably of plastics material, at the end faces of the elongated body, wherein at least one outer surface of the elongated body constitutes a preferred measuring surface.
2. Description of the Related Art
Levels have been for decades manufactured all over the world in large numbers and are used regularly primarily in civil engineering. For reasons of strength and dimensional stability, the body of a level is usually composed of metal, in most cases light metal, and conventionally has a rectangular hollow cross section or a I-shaped solid cross section. In order to prevent damage to the levels in case of impacts or when dropped, the level body is provided with end caps which are composed of a relatively soft, elastic, shock-absorbing material, usually plastics material. When the level body is of a hollow section, the end caps also serve as closures.
A level with an end cap of plastics material is disclosed, for example, in AT 398 846 B. This level has a level body with an I-shaped cross section. The cross section of the end caps is rectangular and their dimensions are adapted to the dimensions of the level body. For fastening the end caps to the level body, the end faces of the level body are provided with two blind-end openings which have several undercuts. The end caps are provided with appropriate lugs which engage positively in the blind-end openings. In this manner, the end caps are inseparably fastened to the level body.
In the manufacture of levels, there is the tendency to construct the shock absorbers at the end caps larger and larger in order to achieve a better protection against damage. However, end caps which are manufactured as injection molded articles have manufacturing tolerances and also have a different coefficient of expansion than the level body. In order to prevent the end caps from projecting beyond the measuring surfaces of the level, the end caps are manufactured with smaller cross sectional dimensions than the level bodies; in addition, also for aesthetic reasons, the end caps are frequently slightly outwardly conically bevelled. The smaller cross sectional dimensions result in an undesirable step in the plane of the measuring surface in the joining area between the end cap and the level body.
This has the result that, for example, in the corner area of two walls where a line or marking has to be transferred from one wall to the other, the line or marking cannot be continued precisely around the corner because the measuring surface of the level cannot be placed all the way into the corner because of the presence of the end cap mounted on the end face of the level body. The greater the length of the portion with no line or marking, the more effective the shock absorption of the end cap. This results in inaccuracies.
Many artisans solve this problem by pulling off the end cap by applying great force. However, since the end caps are not designed for such a use, they find no support when they are once again inserted into the level body; rather, the end caps remain separate and become lost. This is not satisfactory.